Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965140AbWL2Xqv (ORCPT ); Fri, 29 Dec 2006 18:46:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965169AbWL2Xqv (ORCPT ); Fri, 29 Dec 2006 18:46:51 -0500 Received: from saraswathi.solana.com ([198.99.130.12]:45681 "EHLO saraswathi.solana.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965140AbWL2Xqu (ORCPT ); Fri, 29 Dec 2006 18:46:50 -0500 Message-Id: <200612292341.kBTNfUqs005544@ccure.user-mode-linux.org> X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.0.4 To: akpm@osdl.org cc: linux-kernel@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net Subject: [PATCH 4/6] UML - Lock the irqs_to_free list Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Fri, 29 Dec 2006 18:41:30 -0500 From: Jeff Dike Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1992 Lines: 60 Fix (i.e. add some) the locking around the irqs_to_free list. Signed-off-by: Jeff Dike -- arch/um/drivers/chan_kern.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) Index: linux-2.6.18-mm/arch/um/drivers/chan_kern.c =================================================================== --- linux-2.6.18-mm.orig/arch/um/drivers/chan_kern.c 2006-12-29 15:27:16.000000000 -0500 +++ linux-2.6.18-mm/arch/um/drivers/chan_kern.c 2006-12-29 16:38:43.000000000 -0500 @@ -222,15 +222,28 @@ void enable_chan(struct line *line) } } +/* Items are added in IRQ context, when free_irq can't be called, and + * removed in process context, when it can. + * This handles interrupt sources which disappear, and which need to + * be permanently disabled. This is discovered in IRQ context, but + * the freeing of the IRQ must be done later. + */ +static DEFINE_SPINLOCK(irqs_to_free_lock); static LIST_HEAD(irqs_to_free); void free_irqs(void) { struct chan *chan; + LIST_HEAD(list); + struct list_head *ele; + + spin_lock_irq(&irqs_to_free_lock); + list_splice_init(&irqs_to_free, &list); + INIT_LIST_HEAD(&irqs_to_free); + spin_unlock_irq(&irqs_to_free_lock); - while(!list_empty(&irqs_to_free)){ - chan = list_entry(irqs_to_free.next, struct chan, free_list); - list_del(&chan->free_list); + list_for_each(ele, &list){ + chan = list_entry(ele, struct chan, free_list); if(chan->input) free_irq(chan->line->driver->read_irq, chan); @@ -246,7 +259,9 @@ static void close_one_chan(struct chan * return; if(delay_free_irq){ + spin_lock_irq(&irqs_to_free_lock); list_add(&chan->free_list, &irqs_to_free); + spin_unlock_irq(&irqs_to_free_lock); } else { if(chan->input) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/